1. Field of the Invention
The present invention relates generally to an electrical connector, and more particularly to an improvement in an electrical connector used for putting connecting terminals provided on a circuit board, such as a flexible printed circuit board (FPC), conductors provided in a flexible flat cable assembly (FFC) or the like in electrical connection with conductive circuit pattern portions formed on a main circuit board.
2. Description of the Prior Art
In the field of electronic apparatus including a mobile telephone, a portable telephone with a camera and so on, a relatively small-sized flexible printed circuit board is often mounted on a main printed circuit board, on which various electrical parts are directly mounted, by means of an electrical connector which is fixed to and connected electrically with the main printed circuit board. The electrical connector has a plurality of conductive contacts for coming into contact with connecting terminals provided on the flexible printed circuit board and is operative to connect, through the conductive contacts, the connecting terminals provided with the flexible printed circuit board with conductive circuit pattern portions formed in print on the main printed circuit board.
For example, a previously proposed electrical connector, which is used for mounting a flexible printed circuit board on a main printed circuit board, is provided with a housing made of insulator which has an opening through which the flexible printed circuit board is partially inserted into the housing. In the housing, a plurality of conductive contacts are arranged along the opening. These conductive contacts are operative to come into contact with a plurality of connecting terminals provided on the flexible printed circuit board when the flexible printed circuit board is partially inserted into the housing through the opening. The electrical connector is further provided with an actuator which is attached rotatably to the housing to be common to the conductive contacts arranged in the housing. When the actuator is rotated in regard to the housing, each of the conductive contacts is partially moved in the housing.
Each of the conductive contacts arranged in the housing is made of conductive resilient material to have a fixed portion which is fixed to the housing and a movable portion coupled with the fixed portion. The fixed portion of the conductive contact is connected electrically with a conductive circuit pattern portion provided on the main printed circuit board. The movable portion of the conductive contact constitutes an operating part which is moved by the actuator.
In the previously proposed electrical connector as mentioned above, when the flexible printed circuit board is partially inserted into the housing through the opening provided thereon and the actuator is rotated in a predetermined direction, the actuator operates to move the movable portion of each of the conductive contacts to come into press-contact with a corresponding one of the connecting terminals provided on the flexible printed circuit board, as shown in, for example, the Japanese patent application published before examination under publication number 2002-270290 (A publication document). Then, when the actuator by which the operating part of each of the conductive contacts is brought into press-contact with the corresponding connecting terminal provided on the flexible printed circuit board is rotated in a direction opposite to the predetermined direction, the movable portion of each of the conductive contacts is allowed by the actuator to move for getting out of press-contact with the corresponding connecting terminal provided on the flexible printed circuit board.
In such an electrical connector as shown in the published document, as shown in FIG. 1, a plurality of conductive contacts 13 are arranged on a housing 12 made of insulating material and attached to a main printed circuit board 11 and an actuator 14 is provided also on the housing 12 to be rotateble to the same. When the electrical connector thus constituted is put in its function, first, the actuator 14 is postured to take up a first station in which the actuator 14 keeps rising from the housing 12, as shown in FIG. 1. Then, a flexible printed circuit board 15 is partially inserted into the housing 12 through an opening provided on the housing 12 and the actuator 14 is rotated to shift from the first station to a second station in which the actuator 14 keeps lying down on the housing 12, as shown in FIG. 2. Thereby, a movable portion serving as an operating part of each of the conductive contacts 13 is moved by the actuator 14 to come into press-contact with a corresponding one of a plurality of connecting terminals 20 provided on the flexible printed circuit board 15.
Each of the conductive contacts 13 is made of conductive resilient material and formed into an H-shaped member, as shown in FIG. 3. The conductive contact 13 has a pair of beams 17 and 18 coupled with each other through a connecting portion 16. The beam 17 constitutes a fixed portion of the conductive contact 13 and the beam 18 constitutes the movable portion of the conductive contact 13. An end portion 17a of the beam 17 is electrically connected with a conductive circuit pattern portion 19 provided on the main printed circuit board 11.
The actuator 14 has a plurality of engaging portions 21 operative to engage with the conductive contacts 13, respectively, as shown in FIG. 3.
When the flexible printed circuit board 15 is partially inserted into the housing 12 through the opening provided thereon, a part of the flexible printed circuit board 15 on which the connecting terminals 20 are provided is placed between the beam 17 and the beam 18 of each of the conductive contacts 13. The engaging portion 21 of the actuator 14 which is in the second station to keep lying down on the housing 12 engages with the conductive contact 13 for moving the beam 18 of the conductive contact 13 so as to cause an end portion 18a of the beam 18 to come into press-contact with the corresponding connecting terminal 20 provided on the part of the flexible printed circuit board 15, as shown in FIG. 3. Thereby, the part of the flexible printed circuit board 15 on which the connecting terminal 20 are provided and inserted into the housing 12 is held by the beams 17 and 18 of each of the conductive contacts 13.
When the actuator 14 is in the second station to keep lying down on the housing 12, as shown in FIGS. 2 and 3, a vacant space 22 is formed between a portion of the main printed circuit board 11 adjacent to the conductive circuit pattern portions 19, with which the end portions 17a of the beams 17 are electrically connected, respectively, and a part of the actuator 14 facing the same portion of the main printed circuit board 11. This vacant space 22 allows dust or mote to pass through the vacant space 22 and to stick to the conductive circuit pattern portion 19 and the end portion 17a of the beam 17 connected electrically with the conductive circuit pattern portion 19. Therefore, it is seriously feared that such sticking of dust or mote as mentioned above brings about disadvantages or problems of defective conduction between the end portion 17a of the beam 17 and the conductive circuit pattern portion 19, an undesirable short circuit between the end portions 17a of the beams 17, an undesirable short circuit between the conductive circuit pattern portions 19 and so on.
Accordingly, it has been previously proposed to apply an adhesive agent which sets after applied on the main printed circuit board 11 to form a wall 23 of stiffened adhesive agent, as shown in FIG. 3. The wall 23 of stiffened adhesive agent blocks up the vacant space 22 between the portion of the main printed circuit board 11 adjacent to the conductive circuit pattern portions 19 and the part of the actuator 14 facing the same portion of the main printed circuit board 11.
In the case of the electrical connector thus proposed previously to be used for mounting the flexible printed circuit board on the main printed circuit board, in which when the flexible printed circuit board is partially inserted into the housing through the opening provided thereon and the actuator is postured to keep lying down on the housing for causing the movable portion of each of the conductive contacts to come into press-contact with the corresponding connecting terminal provided on the flexible printed circuit board, the vacant space formed between the portion of the main printed circuit board adjacent to the conductive circuit pattern portions, with which the conductive contacts are electrically connected, respectively, and the part of the actuator facing the same portion of the main printed circuit board, is blocked up by the wall of stiffened adhesive agent, disadvantages accompanied with formation of the wall of stiffened adhesive agent are brought about. That is, the disadvantages that the amount of work for mounting the flexible printed circuit board on the main printed circuit board is increased by applying the adhesive agent on the main printed circuit board, it is additionally required to control the adhesive agent applied on the main printed circuit board in its quantity, and it is not easy to form appropriately the wall of stiffened adhesive agent functioning effectively, are accompanied with the formation of the wall of stiffened adhesive agent.